In general, a clothes dryer is a device that absorbs moisture from objects to be dried (load) by blowing hot air generated by a heater into a drum and thereby dries the load. Clothes dryers may be roughly categorized into an exhaust type clothes dryer and a condensation type clothes dryer, according to the method employed for handling the humid air occurring when absorbing the moisture and drying the load.
The exhaust type clothes dryer employs a method for exhausting the humid air flowing from the drum to the outside of the dryer. However, it requires an exhaust duct for exhausting the moisture evaporated in the drum to the outside. In particular, when gas heating is employed, the exhaust duct needs to be installed being extended long enough to the outdoors, considering that carbon monoxide, etc. as a product of combustion are also exhausted.
The condensation type clothes dryer uses a recirculation method that removes moisture by condensing the moisture from the humid air flowing from the drum in a heat exchanger and then re-circulates the moisture-removed dry air back into the drum. However, the drying air flow forms a closed loop, making it difficult to use gas as a heating source.
A ductless dryer overcomes the demerits of the exhaust type dryer and the condensation type dryer. That is, the ductless dryer uses a method that removes moisture by condensing the moisture from the humid air flowing from the drum in a heat exchanger and then exhausts the moisture-removed dry air to the outside. Accordingly, the ductless dryer can be maintained at a low cost by using gas as the heating source and does not require an additional exhaust duct to be extended to the outdoors.
Meanwhile, the condensation type dryer and the ductless dryer may include a filter for filtering lint, since the lint detached from laundry during a drying operation may be contained in air coming out of the drum and thereby be introduced to the heat exchanger. However, an installation of the filter cannot completely prevent a leakage of lint.
For instance, a screen filter is formed of a plastic material, and a portion where the screen filter is installed is formed of steel. Accordingly, due to such different materials, it is difficult to completely seal the screen filter and the installation portion of the screen filter, thereby causing the leakage of lint. A butterfly filter as another example also causes the leakage of lint due to the lack of a sealing structure in a portion where the butterfly filter is installed.
The thusly leaked lint is introduced into the heat exchanger with air, and accumulated (piled up) on a surface of the heat exchanger. In the condensation type dryer, air flowing from the heat exchanger may not be smoothly circulated by a resistance due to such lint. In the ductless dryer, the air flowing from the heat exchanger may not be smoothly exhausted to the outside, thereby deteriorating drying performance. In addition, due to the link accumulated on the surface of the heat exchanger, heat cannot be smoothly exchanged in the heat exchanger, thereby deteriorating heat exchange efficiency.